Cabinet-cover counterbalancing mechanism



Aug. 13, 1957 c. B. ULRICH, sR

CABINET-COVER COUNTERBALANCING MECHANISM Filed Jan. 16, 1956 4`..|..\\\ 033% ASS o United States Patent O M CABINET-COVER COUNTERBALAN CIN M'ECHAN ISM Charles B. Ulrich, Sr., deceased, late of Jamestown, N. Y., by Charles B. Ulrich, Jr., executor, Jamestown, N. Y.

Application January 16, 1956, Serial No. 559,345

8 Claims. (Cl. S12- 319) This invention relates to counter-balanced receptacle covers, particularly for cabinets of large dimensions and for which the covers are rather heavy and present a problem of easy opening and closing. Such a cabinet is one of the type used for vertical storing of what is commonly called plan-tiles. Architects and engineers drawings, prints and tracings, oifset prints and metal negatives for printers, X-ray prints for hospitals and clinics, art store prints and unmounted paintings, most of which measure 18 to 24 inches at least for one dimension, require rather large size cabinets. Moreover, such cabinets have to be of fire-proof construction, hence the top-opening covers are rather heavy. There is an advantage, therefore, in having them counterbalanced to make their opening and closing more facile and convenient.

The main objects of this invention are to provide an improved form of counterbalance mechanism for verticalswinging cabinet covers; to provide a counterbalancing spring wherein the tensioning of the spring is automatically accommodated to the changing gravitational force of the angularly-moving cover; to provide improved means for adjustably varying the tensioning of the spring; to provide improved means for cushioning the counterbalancing force of the spring as the cover approaches its fully-open position; to provide improved means for retainingthe cover in its vertically-open position against accidental displacement; and to provide an improved counterbalancing mechanism of this kind which is simple in construction, hence economical to manufacture, effective in functioning, and possessing a minimum incident of failure or repair.

In the adaptation shown in the accompanying drawings:

Fig. 1 is a vertical, cross section of a planle cabinet of the above-noted type, equipped with an improved counterbalancing mechanism constructed in accordance with this invention, the cover and the counterbalancing mechanism being shown in full outline in their verticallyopen and retracted positions and in dotted outline in their closed retracted and extended cover-lifting positions.

Fig. 2 i-s an enlarged, fragmentary, sectional View taken on the plane of the 'line 2-2 of Fig. 1;

Fig. 3 is an enlarged, fragmentary, sectional view taken on the plane of the line 3-3 of Fig. 1;

Fig. 4 is a fragmentary detail of one end of the counterbalancing spring; and

Fig. 5 is a fragmentary detail showing a removable plate over a cabinet hand-hole through which access may be had for adjusting the tension of the counterbalancing spring.

The essential concept of this invention involves a control arm hinged to the cover and mounting a sheave on its opposite end so engaging a tensioning spring, spanning the horizontal distance between brackets arranged adjacent the front and back walls of the cabinet, as to extend the spring nearly the full depth of the cabinet during the vertical travel of the sheave resulting from the guided movement of the control arm during the closing and opening of the cover.

A cover-counterbalancing mechanism, for use with ICC Patented Aug. 13, 1957 mechanism is especially adapted for use, is constructed for the vertical storage of large-size items, such as those' hereinbefore noted. Items of this kind generally are suspended from bars variously supported on racks arranged at the top of the cabinet. l

. Such a cabinet A is provided with a cover 6, hinged at 7 along one edge, for swinging in a vertical plane between its closed position-as shown Vin dotted outline in Fig. land its fully-open, vertically-disposed position-shown in full outline in Fig. l.

A cabinet A, and its cover 6, for the above kind of use, is an insulated, double-wall construction to render it ireproof. Consequently, the cover 6 is likely to be of a fairly heavy character. A counterbalancing mechanism, therefore, will make its opening and closing more convenient for those who have the responsibility for doing so day after day--if not several times each day.

The control arm B is hinged at one end to a bracket 8 on the cover 6 and at the other end mounts a sheave 9 for resting on and partially embracing the spring C.

The bracket 8 here is shown in the form of an angle bar (see Fig. 2) one leg 11 of which is bonded to the top of the cover 6 to dispose the other bracket leg 12 transversely inward from the cover top. Such a bracket 8 is bonded to the cover substantially medially of the front and rear edges in ordery to secure the most elective tensioning of the spring C. j

The hinge connection of the arm B and bracket 8 preferably is a roller or ball bearing 13. The arm B extends through a slot-like opening 14 in the top face of one of the side walls of the cabinet A. The arm B i-s of a length that, with the cover 6 in its fully-open, vertically-disposed position, the sheave 9 is located just inwardly of the top edge of the cabinet side wall. The inner end of the arm B is somewhat enlarged and formed with an oifset hub 16 for supporting a journal pin 17 for a roller bearing 18.

The spring C is a conventional cylindrical-coiled spring. The convolutions at each end are reduced in diameter to retain attached thereto the headed hooks 19 (see Fig. 4). The spring C is operatively positioned by having the hooks- 19 seated in one of the several apertures 21 formed in each of the triangular-shaped plates 22.

The plates 22 are secured within the cabinet adjacent the side wall and the front and rear walls respectively, also a-djacent the upper edges thereof. The plates 22 are so arranged that With the spring C fully retracted it would be nearly horizontally-disposed a very short distance n- Wardly from the top edge of the cabinet Walls. However, with the arm B retained in position by the cushioning and retaining idevice D (as shown in Fig. l) the spring C is slightly tensioned and therefore angles slightly from a more-nearly horizontal disposition which it would occupy were it not thus tensioned.

Obviously, the positioning and consequent tensioning of the spring C, initially and operatively, may be varied by altering the position of the hooks 19 in the plate apertures 21. l

The cover-cushioning and -retaining device D comprises shoulders 23 and 24 on the arm B and stops 26 and 27 on the cabinet A.

The shoulders 23 and 24 are formed by a slot 25 in The stop 26 is an integral projection .on a plate 29 suitably secured to the inner face of the cabinet side wall just below and rearwardly of the slot 14. The stop 26 is so formed as to dispose its outer extremity at right angles to the arm B and in position to be engaged by the shoulder 23 to yieldingly retain the cover 6 in its fully-open, vertically-disposed position.

The stop 27 is in the nature of an angular-shaped pawl pivoted at 30 to the plate 29 so as to dispose the outer end of the stop in spaced, substantially-parallel relationship with the stop 26.

A rod 31, iixed on the stop 26 (or on the plate 29), extends through a hole in the stop 27 and between the stops 26 and 27 is embraced by a coiled spring 32. This spring 32 shifts the stop 27 away from the stop 26 to the limit of the contact of the stop 27 with a pin 33 on the `plate 29.

- A resilient member 34 biases the arm B to insure a seating of the stops 26 and 27 in the arm recess 25 and thus in position to contact with the respective shoulders 23 and 24. The member 34 here is shown in the form of a leaf spring secured to the upper end of a side wall outwardly adjacent of the slot 14. Its outer end being curved and bearing on the front edge of the arm B positions the arm B so that when the cover 6 is approaching or is positioned in its fully-open verticallydisposed position, the lower free end of the arm will be pressed rearwardly to project the stops 26 and 27 into the recess 25 and hence in position to be engaged by the respective shoulders 23 and 24.

Where, as usually might be the case, this counterbalancing mechanism is interposed within one-or both-side walls of the cabinet A, or between a cabinet side wall and an interior sub-wall, it would be convenient to have access to the hook-plate supported ends of the spring C to permit adjustment .of the tension of the spring C. To that end, appropriate hand holes 35 may be formed in the outer side wall adjacent the apertured plates 22. The holes 35 would be covered with easilyremovable cover plates 36 (see Fig. 5).

The operation of this improved counterbalancing mechanism and cushioning and retaining device is substantially as follows:

When it is desired to close the cover 6, the arm B (or arms, if two are used) is pulled forwardly against the action of the spring 34 to disengage the shoulder 23 from the stop 26. The cover 6 then may be pulled forward out of its vertically-disposed position. As the cover continues its forward and downward movement,

toward a horizontally-disposed position to close the cabinet, the increasing gravitational pull or weight is absorbed and stored up in the increasing extension of the spring C.

By reason of the fact that the arm B is medially hinged to the cover 6 the normal tendency of the sheave 9 will be to move downwardly in a vertical plane medially of the cabinet. This will extend the spring C uniformly between its respective ends and its contact with the sheave 9. Such vertical movement of the sheave 9 will be further insured by the pressure of the leaf spring 34 against the front edge of the arm B and the possible sliding contact of the rear edge of the arm B with the end of the stop 26.

The cover 6 is held in its fully-closed position by a spring-actuated latch 37. There is then stored up in the spring C a force available to not only initiate the upward movement of the cover 6-when the latch 37 is released-but to force the cover into its fully-open, vertically-disposed position, if there is no manual restrain applied to the cover.

As the downward travel of `the sheave 9 is in a vertical plane, medially of the cabinet A, so is its upward movement, for the same reasons as explained regarding its downward travel.

As the cover 6 approaches its fully-open, verticallydisposed position the cam surface 28, on the lower back edge of the arm B, rides up over the stop 26 and increases the tension of the yspring 34. As the stop 26 drops off the cam 28, the spring 34 snaps the arm B rearwardly to bring the stop 27 into the path of the shoulder 24. The contact of the shoulder 24 with the stop 27 is cushioned by the compression of the spring 32 and further rearward movement of the cover 6 is arrested. Being thus arrested, the spring 32 tends to press the arm B `downwardly to bring the shoulder 23 into contact with the stop 26 and thereby retain the cover in its fully-open, vertically-disposed position.

Variations and modications in the details of structure and arrangement of the parts may be resorted to within the spirit and coverage of the appended claims.

What is claimed is:

l. A cabinet-cover counterbalancing mechanism comprising, a cylindrical coiled spring attachable at its ends to opposite vertical walls of the cabinet for nearly horizontal disposition adjacentA the cabinet open top when the spring is retracted, a control arm, a sheave journaled on one end of the arm, and means for hinging the other end of the arm to the cabinet cover to dispose the arm in the vertical plane of the spring and position the sheave in partially embracing engagement with the spring intermediate the ends thereof, whereby a swinging of the cover is alternately yieldingly resisted and aided by the extended spring.

2. A cabinet-cover counterbalancing mechanism comprising, a cylindrical coiled spring attachable at its ends to opposite vertical walls of the cabinet fornearly horizontal disposition adjacent the cabinet open top when the spring is retracted, a control arm, a sheave journaled on one end of the arm, means for hinging the other end of the arm to the cabinet cover to dispose the arm in the vertical plane of the spring and position the sheave in partially embracing engagement with the spring intermediate the ends thereof, and means for guiding the control arm to insure movement of the sheave in a vertical plane medially of the cabinet in the sheaves contact with the spring during the swinging of the cover, whereby a swinging of the cover is alternately yieldingly resisted and aided by the -extended spring.

3. A cabinet having a cover hinged thereon for vertical swinging, a cylindrical coiled spring attached at its end to oppositewalls of the cabinet adjacent the open top to dispose the spring in a nearly horizontal plane when retracted, a control arm hinged at one end to the cover medially of its front and rear edges and disposed in the plane of the spring, and a sheave journaled on the opposite end of the arm and having partially embracing engagement with the spring intermediate its ends, whereby a swinging of the cover is alternately yieldingly resisted and aided by the extended spring.

4. A cabinet having a cover hinged thereto for vertical swinging, a cylindrical coiled spring attached at its end to opposite walls of the cabinet adjacent the open top to dispose the spring in a nearly horizontal plane when retracted, a control arm hinged at one end to the cover medially of its front and rear edges and disposed in the plane of the spring, a sheave journaled on the opposite end of the arm and having partially embracing engagement with the spring intermediate its ends, and means on the cabinet for contact with the control arm to insure movement of the sheave to a vertical plane medially of the cabinet in the sheaves contact with the spring during the swinging yof the cover, whereby a swinging of the cover is alternately yieldingly resisted and aided by the extended spring.

5. An open top cabinet having a slot-like opening in one of the side walls substantially medially of the front and back cabinet walls, a cover hinged to the cabinet for vertical swinging, a pair of angularly-disposed brackets secured to the cabinet adjacent the upper ends of the front and rear walls thereof, each of the brackets having a series of apertures formed therein, a cylindrical coiled spring having hooked ends thereon selectively positioned in the bracket apertures to dispose the retracted spring nearly horizontally adjacent the cabinet open top, a cover control arm hinged at one end to the cover medially of its front and rear edges and extending downwardly through the cabinet side-wall opening in the plane of the spring, and a sheave journaled on the lower end of the arm and having partial embracing engagement with the spring adjacent a medial point thereof, whereby the swinging of the cover is alternately yieldingly resisted and aided by the extended spring.

6. A cabinet having a cover hinged thereto for vertical swinging, a cylindrical coiled spring attached at its end to opposite walls of the cabinet adjacent the open top to dispose the spring in a nearly horizontal plane when retracted, a control arm hinged at one end to the cover medially of its front and rear edges and disposed in the plane of the spring, a sheave journaled on the opposite end of the arm and having partially embracing engagement with the spring intermediate its ends, whereby a swinging of the cover is alternately yieldingly resisted and aided by the extended spring, and coating resilient means on the cabinet and arm for cushioning the swinging of the cover into its fully-open vertically-disposed position by the unrestrained action of the extended spring.

7. An open top cabinet having a slot-like opening in one of the side walls substantially medially of the front and back cabinet walls, a cover hinged to the cabinet for vertical swinging, a pair of angularly-disposed brackets secured to the cabinet adjacent the upper ends of the front and rear walls thereof, each of the brackets having a series of apertures formed therein, a cylindrical coiled spring having hooked ends thereon selectively positioned in the bracket apertures to dispose the retracted spring nearly horizontally adjacent the cabinet open top, a cover control arm hinged at one end to the cover medially of its front and rear edges and extending downwardly through the cabinet side-wall opening in the plane of the spring, a sheave journaled on the lower end of the arm and having partial embracing engagement with the spring adjacent a medial point thereof, whereby the swinging of the cover is alternately yieldingly resisted and aided by the extended spring, the under edge of the arm adjacent the sheave being recessed to form a pair of spaced shoulders, a cam surface on the arm forming an approach to the recess, a pair of substantially-parallel relatively-movable spaced stops mounted on the cabinet adjacent the open top in position to have the outer ends of the stops seated in the arm recess when the cover is in its fullyopen vertically-disposed position, and resilient means normally urging the stops apart whereby the engagement of one of the stops with one of the recess shoulders yieldingly retards the movement of the cover into its fully-'opening vertically-disposed position and the engagement of the yother stop with the other recess shoulder retains the cover in its fully-open vertically-disposed position.

8. An open top cabinet having a slot-like opening in one of the side Walls substantially medially of the front and back cabinet Walls, a cover hinged to the cabinet for vertical swinging, a pair of augularly-disposed brackets secured to the cabinet adjacent the upper ends of the front and rear walls thereof, each of the brackets having a series `of apertures formed Itherein, a cylindrical coiled spring having hooked ends thereon selectively positioned in the bracket apertures to dispose the retracted spring nearly horizontally adjacent the cabinet open top, a cover control arm hinged at one end to the cover medially of its front and rear edges and extending downwardly through the cabinet side-wall opening in the plane of the spring, a sheave journaled on the lower end of the arm and having partial embracing engagement with the spring adjacent a medial point thereof, whereby the swinging of the cover is alternately yieldingly resisted and aided by the extended spring, the under edge of the arm adjacent the sheave being recessed to form a pair of spaced shoulders, a cam surface on the arm forming an approach to the recess, a pair of substantiallyparallel relatively-movable spaced stops mounted on the cabinet adjacent the open top in position to have the outer ends of the stops seated in the arm recess when the cover is in its fully-open vertically-disposed position, resilient means normally urging the stops apart whereby the engagement of one of the stops with one of the recess shoulders yieldingly retards the movement of the cover into its fully-opening vertically-disposed position and the engagement of the other stop with the other recess shoulder retains the cover in its fully-open vertically-disposed position, and means biasing the arm to seat the stops in the arm recess when the cover is in its fully-open verticallydisposed position.

References Cited in the le of this patent UNITED STATES PATENTS 1,106,640 Eccleston Aug. 11, 1914 1,350,134 Bellican Aug. 17, 1920 2,085,479 Shater et al. June 29, 1937 

